# Tag Info

Accepted

### Royal road to Abstract Harmonic Analysis?

Rudin's 'Fourier analysis on groups' is one of the most enjoyable books I ever read. How well versed are you in classical harmonic analysis? the books by Katznelson and by Helson go a long way toward ...
• 12.9k
Accepted

### Cohomology over "discrete reals" vs "continuous reals"?

Because $\mathbb{R}$ is contractible, so are all $B^n\mathbb{R}_{\text{continuous}}$. So $H^n(X;\mathbb{R}_{\text{continuous}}) = 0$ for all $X$.
• 150

### Reference request: Tiling the plane with congruent snowflakes

I couldn't find any discussion of this problem online, so I went ahead myself and made an algorithm which can exhaustively generate the figures described, given a few extra assumptions. The linked ...
• 101
Accepted

### How many connected bipartite graphs are there?

The probability that the uniform random graph will be bipartite is in fact extremely low. It is not straightforward to compute exactly, because there is a large number of ways for it to happen, and ...
• 114k

### Herbert Amann Analysis vs Zorich Analysis

I was interested in this question, too, but also nowhere found a direct answer to it, except on a german website called matheplanet (you may translate the reviews/comments). But I can tell you ...
• 21
Accepted

### Generalized Stochastic Matrices with Negative Transition Probabilities

You need more than $\ |\lambda_j|\le1\$ to get convergence of $\ A^k\$. If $$A=\pmatrix{1&0&0\\0&-1&2\\ 0&0&1}\ ,$$ for instance, the eigenvalues of $\ A\$ are $\ 1,-1\$ ...
• 20.4k

### First-order logic with finitistic approach

Here is as paper on a formal system for "feasible" numbers. As Alex Kruckman suggests, the paper often just refers to existing theory on formal logic for background. The main novel ...
• 2,659
Accepted

### Attempting to restate the question of whether the collatz conjecture has a nontrivial cycle as a combinatorics problem

Just to add some more combinatorical information. Preamble: I'm used to use the following letters, which are different from yours, and I'm lazy to adapt this, please bare with me... I use $N$ for ...
• 32.8k

### Higher-Order Differential Operators as Vector Fields

The velocity of a particle on a curved space is a covariant notion but acceleration isn't. They appear to be very similar concepts in flat space because we represent them in the same way, but on ...
• 5,672
1 vote
Accepted

### Defining a Coxeter group using all reflections

What you're asking about is what's sometimes called the "dual approach" to reflection groups and their braid groups. A good place to start would be D. Bessis, The Dual Braid Monoid, https:/...
• 71
1 vote
Accepted

### Reference request for elementary geometry.

I can think on several options, one of them is Elementary Geometry from an advanced standpoint by E.Moise. But if you are looking for exercises like in math olympiads, there is a lot of material like ...
1 vote
Accepted